Quick disconnect hose coupling assemblies provide reliable and easy connections. Quick disconnect coupling assemblies are ubiquitous and are available from many manufacturers. The parts are generally interchangeable even if made by different manufacturers. The design of the coupling assemblies permits a male plug, also known as a nipple, to quickly mate with a female socket. When the plug is fitted with the socket, hardened pins or balls in the socket engage a groove or ridge on the plug. This locks the assembly in place and provides a generally fluid-tight seal. The assembly is still able to swivel 360 degrees when locked to prevent twisting of the hose. To unlock the assembly, a retractable sleeve is provided on the socket. Retracting the sleeve disengages the pins or balls from the groove or ridge. The socket than can be pulled away from the plug to disengage the assembly. The assembly will not disengage unless the sleeve is retracted.
One illustrative application of quick disconnect hose coupling assemblies is used on pavement markers, i.e., devices that are used to spread paint or film as markings onto pavements or curbs. One common device for applying or reapplying markings known in the art as a xe2x80x9cflame sprayer,xe2x80x9d such as the Green Light GLG-20 brand flame sprayer manufactured by the 3M Company of St. Paul, Minn. The flame sprayer ignites a fuel such as propane to heat a thermal powder sprayed from a nozzle. The thermal powder is thus converted into a xe2x80x9cpaintxe2x80x9d that readily adheres to a pavement surface. An operator rolls the flame sprayer along the pavement as the flame sprayer sprays the pavement. A quick disconnect hose coupling assembly is used to connect the flame-sprayer to a remote air compressor that supplies pressurized air to apply the paint.
One disadvantage of the quick disconnect hose coupling assembly is that the hose, or the apparatus connected to the hose, will become damaged if the hose is pulled without first unlocking the socket from the plug. For example, flame sprayers are often used in the vicinity of traffic. If the hose were to catch on a passing vehicle, the coupling assembly would not disengage. The resulting force on the coupling assembly attached to the flame sprayer would likely first knock over the flame sprayer, causing damage to the flame sprayer and spilling the powder, and then rip the hose from the hose coupling assembly. This is one illustration of many situations where pulling on a hose connected to an engaged assembly will damage the hose or connected apparatus. Accordingly, there is a need in the art for a hose coupling assembly that will reduce the potential for damage and will disengage if the hose is accidentally pulled.
The present disclosure relates to quick disconnect and release hose couplings where the socket will disconnect and release from a plug if the hose connected to the hose coupling is pulled with sufficient force. Thus, if in the flame sprayer example above, a passing vehicle catches the hose, the hose coupling assembly will release the hose from the flame sprayer. This should reduce the amount of damage to the hose and flame sprayer if they were connected with other types of quick disconnect assemblies.
A suitable quick disconnect female socket used in the hose coupling includes a body portion and a movable sleeve. The hose coupling includes an end conduit that is adapted for coupling to a hose. The end conduit is connected to an intermediate conduit, and the intermediate conduit is connected to the body portion of the socket. The hose is in fluid communication with the socket through the end conduit and intermediate conduit. The intermediate conduit also permits the end conduit to move relative to the body portion. A mechanical coupling is attached to the end conduit and to the sleeve of the socket such that when the end conduit moves relative to the body portion the mechanical coupling moves the sleeve relative to the body portion. Accordingly, pulling on the end conduit or the hose attached to the end conduit will retract the sleeve so as to disconnect and release the hose coupling from the plug.
Several examples of such couplings are disclosed. On example discloses an end fitting that can be attached to the hose, and an intermediate fitting that is attached to the body portion of the socket. The end fitting and intermediate fittings are slidably connected together such that the end fitting is movable relative to the body portion. A mechanical coupling is attached to the end fitting and clamped onto the sleeve. Thus, as the end fitting is pulled away from the body portion, the sleeve retracts on the socket. Other examples are disclosed, along with alternate designs, and still many more versions are contemplated.